3, 5, 6-substituted uracils



United States Patent 3,352,862 3,5,6-SUBSTITUTED URACILS Harvey M. Loux,Hockessin, DeL, assignor to E. I. du Pont de Nemours and Company,Wilmington, Del., a corporation of Delaware No Drawing. Originalapplication Aug. 17, 1962, Ser. No. 217,521, now Patent No. 3,235,357,dated Feb. 15, 1966. Divided and this application Dec. 27, 1965, Ser.

9 Claims. Cl. 260-260) This application is a division of copendingapplication Ser. No. 217,521, filed Aug. 17, 1962, and now US. PatentNo. 3,235,357, which in turn is a continuationin-part of the followingapplications, now abandoned: application Ser. No. 159,746, filed 'Dec.15, 1961; application Ser. No. 84,980, filed Jan. 25, 1961; applicationSer. No. 48,837, filed Aug. 11, 1960; application Ser. No. 12,959, filedMar. 7, 1960; and application Ser. No. 833,704, filed Aug. 14, 1959.

This invention relates to novel 3,5,6-substituted uracils and theiralkali metal and quaternary ammonium salts. More specifically, thepresent invention is directed to uracil compounds of the formula (I) X nX n -Halogen Halogen Z/ o= on. nok CH3 where:

X is methyl or ethyl;

Y is hydrogen or methyl; and Z is an alkyl group of 1 through 6 carbonatoms, and Halogen includes fluorine, bromine, chlorine, and iodine.

Also included within the invention are the salts of the uracils ofFormula 1 formed with such cations as sodium, potassium, lithium, andquaternary ammonium.

The compounds of this invention represent an outstanding group ofherbicides offering a new and effective method for the control ofundesirable vegetation. These compounds are unique in that they exerttheir action against both broadleaf and grass weeds, are effectiveagainst hard-to-kill nutsedge and perennial grasses such as quack grass,Johnson grass, and Bermuda grass, and are effective on highly adsorptivesubstrates such as railroad ballast, heavy clay soil, and soils high inorganic matter.

This combination of properties makes these compounds useful wherevergeneral weed control is required, such as industrial areas, railroadrights-of-way, and areas adjacent to croplands in agricultural areas.

Especially preferred for their outstanding herbicidal effectiveness arethe following compounds of the invention:

-bromo-3-sec-butyl-6-methyluracil 5-bromo-3-sec-butyl-6-methyluracil,sodium salt 5-chloro-3-sec-butyl-6-methyluracil 5-bromo-3-tert-butyl-6-methyluracil 5-chloro-3 -tert-butyl-6-methyluracil5-bromo-3 3-pentyl) -6-methyluracil 5-chloro-3-(3-pentyl)-6-methyluracil5-bromo-3- 2- 3-methylpentyl) ]-6-methyluracil 5 -chloro-3 [2-3-methylpentyl) ]-6-methyluracil 5-bromo-3-isopropyl-6-methyluracil5-chloro-3-isopropyl-6-methyluracil.

Certain of the compounds of the invention also exhibit selectivehericidal action in crops. By properly select- "ice ing a uracil of theinvention and a rate and time of application, annual grass and broadleafseedlings in such crops as asparagus, corn, flax, sugar cane, pineapple,safflower, peanuts, citrus, alfalfa, strawberries, gladiolus, and stonefruits can be controlled.

By proper selection of rate and time of application, certain of thecompounds can also be used to control weeds growing in dormant crops.

This selective activity and activity on weeds growing in dormant cropsis described in more detail in the examples.

The precise amounts of the compounds to be used in any given situationwill, of course, vary according to the particular end result desired,the use involved, the plant and soil involved, the formulation used, themode of application, prevailing weather conditions, foliage density andlike factors. Since so many variables play a role, it is not possible toindicate a rate of ap plication suitable for all situations. Broadlyspeaking, the compounds are used at levels of about pound per acre toabout 25 pounds per acre. For selective weed control in crops, rates ofA to 8 pounds per acre will generally be used. More of the activematerial can be used to control diflicult-to-kill species growing underadverse conditions. Economic factors, such as inaccessibility of thearea to be treated, e.g., fire breaks in forests, may also favor higherrates, with less frequent treatments.

The compounds of the invention are also found effective against manyaquatic weeds, including algae.

The compounds of this invention are strong absorbers of ultravioletradiation. For example, 5-bromo-3-secbutyl-6-methyluracil has strong endabsorption at about 220 mu and additionally has a broad absorption peakwith a maximum at 277 mu. Its extinction coeflicient is nearly 8000.

Compounds of the invention are, therefore, useful as ultravioletscreening agents. Typically, the compound is milled into a vinyl plasticbefore fabrication in order to retard the deterioration of the plasticby sunlight.

The compounds of this invention are also useful as syntheticintermediates. Reaction of these compounds with the appropriate reagentleads to herbicidal materials described in Ser. No. 364,309, filed May1, 1964, now Patent No. 3,235,363.

The uracils of Formula 1 can be prepared by methods heretofore describedin the literature. For example, one method for the preparation of thesecompounds is illustrated by the following equations:

( E III CHa$=C-COOCHa (CH3)2CHNCO CHaC=C-COOCH;

For more general details, note the publication by Behrend and Myer inAnn., 314, 219' (1901) and also Ber., 33, 622 (1900).

In the method of Equations 2 and 3, the esters of B-amino-a,[3-unsaturated acids are first prepared by react- 3 ing thecorresponding fl-keto esters with aqueous ammonia [Conrad and Epstein,Ben, 20, 3054 (1887)]. These fi-aniino-a,fi-unsaturated esters are thenreacted with an isocyanate in an inert solvent such as toluene orxylene, and heated for a short interval of time at reflux temperature.

The reaction mixture is chilled, filtered, and the filtrate distilled toremove the solvent. Generally, a viscous liquid residue remains which iscrude 3-(3-substitutedureido)-a,fi-unsaturated ester. This can bereacted without further purification with an aqueous alcoholic alkalinesolution at reflux temperature to bring about the desired uracil ringclosure. At this point, the reaction is made slightly acidic with astrong acid such as hydrochloric acid and distilled to remove thealcohol. After the remaining aqueous solution has been chilled, thecorresponding substituted uracil separates as an essentially pure solid.

These uracils may be halogenated in their 5-position as For more detailsof a general nature see J.A.C.S. 61, 1015 (1939); Ann., 305, 314; Ann.,352, 242; and Ann., 441, 192.

Specific details for these reactions are provided in the compoundpreparation examples hereof.

Another method for preparing the uracil starting reactants forhalogenation is illustrated by the following equations:

(5) C H; benzene I I ll acid catalyst OH3CH2 H--NHONH2 CH CCH COOC2H -A-(I111; C) CH 1 CHsCHzGH-NHCNHG=CHCO O CzHi (6) H 0 0 H (1) alkali metalI H alcoholato CH CHQCH-NHGNHC=CHCOOC 11 0 CH3 H CHaCHzCH-N I CH3 N HAccording to Equations 5 and 6, an appropriately substituted urea isreacted with a 18-keto ester or an asubstituted ,B-keto estersubstituted with such radicals as fluorine, chlorine, or bromine, and anacid catalyst, at reflux in a solvent from which water is removedcontinuously. After the water has all been removed, the solution isstripped and taken up in ethanol containing a base such as sodiummethoxide. After a few minutes reflux, the solvent is removed, and theresidual oil taken up in Water and acidified, whereupon the desiredproduct separates in crystalline form.

3-alkyl-5-fluoro-6-methyluracils are preferably prepared according toEquations 5 and 6.

The product formed at the end of the first step, i.e., after the waterhas been removed, is a ureido compound of the type referred to inEquation 5. It can be isolated and purified if desired; however, this ino ne y or advantageous.

These ureido compounds referred to above are believed to exist in eitheror both of two tautomeric forms, as illustrated in the followingequation:

(7) CH3-C=GHCOOO2H5 l CHrC-CHzCOOCzHa a l 0 0 0H3 3:0 CH3 ri norraorrnzn-| I l onaonzt zn (8) O 0 II II 012 CH3 ()=\N I H H They may also beiodinated as follows:

The salts of the uracil compounds of Formula 1 are prepared byconventional methods such as dissolving the free uracil in an aqueous ornonaqueous solution of at least an equimolar amount of a base or basicsalt containing the desired cation. For example, a sodium salt can beprepared by dissolving the uracil in water containing an equimolaramount of sodium hydroxide. The salt can then be isolated from thesolution by removal of the water.

Quaternary ammonium salts of the compounds of Formula 1 are prepared byreacting the substituted uracil with an appropriate quaternary ammoniumhydroxide. lllustrative of such hydroxides are tetramethyl ammoniumhydroxide, tetraethyl ammonium hydroxide, tetrabutyl ammonium hydroxide,dodecyltrimethyl ammonium hydroxide, and dimethyl piperidylium ammoniumhydroxide. Since these hydroxides are generally available in solution,the reaction is most conveniently carried out in the same solvent. Ifthe solvent-free salt is desired, it can be easily prepared by removingthe solvent.

Alternatively, the quaternary ammonium salts of the uracils can beprepared in a dry inert solvent such as toluene or xylene. Theappropriate quaternary ammonium halide is then added with stirring and,if necessary, mild heating. The sodium halide Which forms is removed byfiltration, leaving the quaternary ammonium salt of the uracil insolution. If desired, the solvent-free salt can be prepared by removingthe solvent, preferably in vacuo.

The compounds of the present invention can be readily formulated forherbicidal use by incorporating them with suitable adjuvants.

The amount of active compound in such preparations can vary over a widerange according to need. Generally speaking they will contain from about0.5 to by weight of active ingredient.

Powder and dust preparations can be made by mixing compounds of theinvention with finely-divided solids such as talcs, natural clays,pyrophyllite, diatomaceous earth; flours such as walnut shell, wheat,redwood, soya bean and cotton seed; or inorganic substances such as finesilica, magnesium carbonates, calcium carbonate, calcium phosphates,sufur and lime. These preparations are made by thoroughly blending theactive ingredient and the solid. The particles in such preparations arepreferably less than 50 microns in average diameter.

Water-soluble preparations can be prepared by mixing a compound with analkaline solubilizing agent. Solid bases having a pH of at least 9.5 ina 1% aqueous solution, such as sodium or potassium phosphates,silicates, carbonates, borates, oxides or hydroxides, are suitable. Thepreparations can contain from 0.5 to 80% active ingredient and from 5 to99.5% of the solubilizing agent.

The compounds of the invention can also be formulated as concentratedaqueous suspensions containing from to 50% of the active ingredient.These compositions are prepared by mixing the compound with suspendingagents such as bentonites or hydrated attapulgites and with surfaceactive agents and water and milling the mixture to reduce the particlesize and to disperse the suspending agent.

Granules and pellets can be made by mixing a finely divided compoundwith a suitable clay, moistening this mixture with from to by weight ofwater, and then extruding the mass through a suitable die underpressure. The extrusions are cut into pre-determined lengths and thendried. These pellets can be granulated if desired.

Granules or pellets can also be prepared by spraying a suspension orsolution of a uracil or its salt onto the surface of a preformed granuleof clay, vermiculite or other suitable granular material. If the uracilor salt is in solution, it will penetrate into the pores of the granuleand so will adhere without the aid of a binding agent. When the activematerial is insoluble in the liquid and is carried as a suspension, itis preferable that a binding agent such as goulac, dextrin, swollenstarch, glue or polyvinyl alcohol be added. In either case, the granuleis then dried and ready for use.

Compositions of the actives can also be prepared with nonaqueousliquids. Aliphatic and aromatic hydrocarbons, especially those derivedfrom petroleum and having boiling points of from 125 C. to 400 C. arepreferred. Hydrocarbons having lower boiling points should not be usedbecause of their undesirable volatilization characteristics andflammability. Such compositions may be solutions or suspensionsdepending upon choice of nonaqueous carrier, choice of active, anddesired concentrations. The more concentrated compositions aresuspensions, and are made by milling the components in a mill such as apebble mill until the particles have average diameters of from 1 to 50microns, preferably 5 to 20 microns.

The herbicidal preparations, whatever physical form they take, can alsocontain a surface-active agent. The surfactant renders the preparationsreadily dispersible in liquids and improves their action on waxy leavesand the like. For general application, surface-active agents are used inthe preparations at concentrations of from about 1 to 10%, by Weight.Levels of from 0.5 to 6 parts of surfactant for each part of uracil,however, give unusual and unexpected results. Preparations having thesehigher levels of surfactants show greater herbicidal effectiveness thancan be expected from a consideration of activity of the components usedseparately.

The term surface-active agent is intended to include Wetting agents,dispersing agents, suspending agents and emulsifying agents.Surface-active agents suitable for use are set forth in Detergents andEmulsifiers Annual 1965 John W. McCutcheon, Inc., Morristown, NJ. Othersurface-active agents which can be used in these preparations are listedin US. Patents 2,139,276; 2,412,510; 2,426,417; and 2,655,447.

The preparations can also optionally contain adhesives such as gelatin,blood albumin and such resins as rosin alkyd resins. These increaseretention and tenacity of deposits following application.

The salts of the uracils of Formula 1 are especially advantageous foruse as herbicides because they are soluble in water and can be appliedas aqueous solutions.

The herbicidal compounds of this invention can be combined with eachother and with other known herbicides to give compositions which haveadvantages over the individual components.

Among the known herbicides which can be combined with the compounds ofthe invention are:

SUBSTITUTED UREAS 3-(3,4-dichlorophenyl) -1,1-dimethylurea3-(4-chlorophenyl)-1,1-dimethylurea 3-phenyl-1, l-dimethylurea 3-3,4-dichlorophenyl) -3-methoxy- 1, l-dimethylurea 3- (4-chlorophenyl)-3-methoxy-1, l-dimethylurea 3-(3,4-dichlorophenyl)-1-n-butyl-1-methylurea 3- (3 ,4-dichlorophenyl) -1 -methoxyl-methylurea3- (4-chlorophenyl) -1-methoxyl-rnethylurea 3- (3 ,4-dichlorophenyl)-l,1,3-trimethylurea 3- (3,4-dichlorophenyl) -1,1-diethylurea 3-(p-chlorophenoxyphenyl) -1,1-dimethylnrea These ureas can be mixed withthe compounds of this invention in proportions of from 1:4 to 4: 1,respectively, the preferred ratio being 1:2 to 2:1.

SUBSTITUTED TRIAZINES this invention in proportions of from 1:4 to 4:1,respectively, the preferred ratio being 1:2 to 2:1.

PHENOLS Dinitro-o-sec-butylphenol and its salts Pentachlorophenol andits salts These phenols can be mixed with the compounds of thisinvention in the proportions of 1:10 to 20:1, respectively, thepreferred ratio being 1:5 to 5:1.

CARBOXYLIC ACIDS AND DERIVATIVES The following carboxylic acids andderivatives can be mixed with the compounds of this invention in thelisted proportions:

2,3,6-trichlorobenzoic acid and its salts 2,3,5,6-tetrachlorobenzoicacid and its salts 2-methoxy-3,5,6-trichlorobenzoic acid and its salts 2rnethoxy-3,6-dichlorobenzoic acid and its salts3-amino-2,S-dichlorobenzoic acid and its salts3-nitro-2,5-dichlorobenzoic acid and its salts2-methyl-3,6-dichlorobenzcic acid and its salts2,4-dichlorophenoxyacetic acid and its salts and esters 2,4,5-trichlorophenoxyacetic acid and its salts and esters(2-methyl-4-chlorophenoxy)acetic acid and its salts and esters2-(2,4,5-trichlorophenoxy)propionic acid and its salts and esters2-(2,4,5-trichlorophenoxy)ethyl-2,2-dichloropropionate4-(2,4-dichlorophenoxy)butyric acid and its salts and esters 74-(2-methyl-4-chlorophenoxy)butyric acid and its salts and esters2,3,6-trichlorobenzyloxypropanol mixed in a 1:16 to 8:1 ratio,preferably a 1:4 to 4:1 ratio.

B 2,6-dichlorobenzonitrile mixed in a 1:4 to 4:1 ratio, preferably a 1:3to 3:1 ratio.

Trichloroacetic acid and its salts mixed in a 1:2 to 25 :1 ratio,preferably a 1:1 to 8:1 ratio.

2,2-dichloropropionic acid and its salts mixed in a 1:4 to 8:1 ratio,preferably a 1:2 to 4:1 ratio.

N,N-di(n-propyl)thiolcarbamic acid, ethyl esterN,N-di(n-propyl)thio1carbamic acid, n-propyl esterN-ethyl-N-(n-butyl)thiolcarbamic acid, ethyl esterN-ethyl-N-(n-butyl)thiolcarbamic acid, n-propyl ester mixed in a 1:2 to24:1 ratio, preferably a 1:1 to 12:1

ratio.

N-phenylcarbarnic acid, isopropyl ester N-(m-chlorophenyl)carbamic acid,isopropyl ester N-(m-chlorophenyl)carbamic acid, 4-chloro-2-butynylester mixed in a 1:2 to 24:1 ratio, preferably a 1:1 to 12:1 ratio.

2,3,6-trichlorophenylacetic acid and its salts mixed in a 1:12 to 8 :1ratio, preferably a 1:4 to 4:1 ratio.

2-chloro-N,N-diallylacetamide Maleic hydrazide mixed in a 1:2 to 10:1ratio, preferably a 1:1 to 5:1 ratio.

INORGANIC AND MIXED INORGANIC-ORGANIC SALTS The following salts can bemixed with the compounds of the invention in the listed proportions:

A Calcium propylarsonate Disodium monomethylarsonateOctyl-dodecylamrnoniummethylarsonate Dimethylarsinic acid mixed in a 1:4to 4: 1 ratio, preferably at 1:2 to 2:1 ratio.

B Sodium arsenite mixed in a 1:5 to 40:1 ratio, preferably a 1:4 to 25:1ratio.

C Lead arsenate Calcium arsenate mixed in a 150:1 to 600:1 ratio,preferably a 100:1 to 400:1 ratio.

Sodium tetraborate hydrated, granulated Sodium metaborate Sodiumpentaborate Polyborchlorate Unrefined borate ore such as Borascu mixedin a 3:1 to 150021 ratio, preferably a 6:1 to 1000:1 ratio.

Ammonium thiocyanate mixed in a 1:10 to 20:1 ratio, preferably a 1:5 to5:1 ratio.

F Sodium chlorate mixed in a 1:1 to 40:1 ratio, preferably a 2:1 to 20:1ratio.

Ammonium sulfamate mixed in a 1:1 to :1 ratio, preferably a 1:1 to 50:1ratio.

OTHER ORGANIC HERBICIDES These organic herbicides can be mixed with thecompounds of the invention in the listed proportions:

Hexachloroacetone mixed in a 1:2 to 16:1 ratio, preferably a 1:1 to 8:1ratio.

E Diphenylacetonitrile N,N,dimethyl-a,u-diphenylacetamideN,N-di-n-propyl-2,6-dinitro-4-trifiuormethylanilineN,N-di-n-propyl-2,6-dinitro-4-methylaniline mixed in a 1:10 to 30:1ratio, preferably a 1:5 to 20:1 ratio.

0 (2,4 dichlorophenyl)-0-methy1 isopropylphosphoramidothiate2,3,5,6-tetrachloroterephthalic acid, dimethyl ester mixed in a 1:4 to20:1 ratio, preferably a 1:3 to 15:1 ratio.

2,4-dichloro-4'-nitrodipheny1 ether 2,3,5-trichloro-4-pyridino14-amino-3-5,6-trichloropicolinic acid mixed in a 1:10 to 30:1 ratio,preferably a 1:5 to 20:1 ratio.

OTHER SUBSTITUTED URACILS These uracils can be mixed with other knownherbicidal uracils, in the proportions listed below.

3-cyclohexyl-6-methyluracil 3-cyclohexyl-6-ethyluracil3-cyclohexyl-6-sec-buty1uraci1 3-norbornyl-6-methyluracil3-cyclopentyl-6-methyluracil 3-cyclohexyl-6-isopropyluracil mixed in a1:4 to 4:1 ratio, preferably a 1:2 to 2:1 ratio.

3-cyclohexyl-5,G-trimethyleneuracil 3-sec-butyl-5,6-trimethyleneuracil3-isopropyl-5,6-trimethyleneuracil 3-isopropyl-5,6-tetramethyleneuracil3-isopropyl-S,6-pentamethyleneuracil mixed in a 1:6 to 6:1 ratio,preferably a 1:4 to 4:1 ratio.

Uracil Starting Reactaut Parts by Weight Uracil Product3-isopropyl-6-methyluracil 168 -br0mo-3-isopropyl-6-methyluraeil.6-methy13-(2-penty1)uraeil 196 5-bron1o-6-methyl-3-(2-pentyl)urae1l. I6methyl-3-[2-(3-methylbutyl)]urac1l 196 5-brom0-6-methy1-3-[2-(S-methylbutyl) ]urac11. 6-methyl-3-(3-pentyl)uracil 1965-bromo-6-methyl-3-(3-pentyl)uracil. 3-(2-hexyl)-6-methy1u raei1 r 2105-brom0-3-(2-hexyl)-6-methy1urac1l. 6-methyl-3-[2-(3-methylpentyl)]urac210 5-bromo-6-methyl-3f[2-(3-methylpentyl)]uracil. 3[2-(3,3-dimethy1butyl)l-fi-methyluracil 210 5-br0m0-3-[2- (3,a-dnnethylbutyl)]-6-methylurae1l. 6-methyl-3-[2-( kmethylpentylfluracil210 5-br0mo-6-metl1yl-3-[2-(4methylpentyl)]urac1l.3-(3-hexyD-6-methyluraci1 210 5-bromo-3-(3-hexyl)-6-methylurae1l.6-methyl-3-[3-(2-methylpentyl)]ur 2105-br0rno-6-methyl-3-[3-(2-methylpentyl)]urac1l. 3- (3-heptyl)-6-methyluraci1 1 224 5-bromo-3- (3-hepty1) -6-methylurac1l.6-methyl-3-[3-(4-methylhexy1)]uracil 224 5-bromo-6-methyl-3-[3- (4-methylhexyl)]urac1i. 3-[3-(4, 4-dimothylpentyl)]-6-methylu.racil 2245-bromo-6-methyl-3-[3-(4, 4-dunethylpenty l)]urae1l.6-methy1-3-[3-(5-methy1hexyl)]uracil 2245-br0m0-6-mcthy1'[3-(5-methy1hexy121urac1l. 3-(tert-butyl)-6-methy1uraoil 182 5-bromo-3-(tert-butyl)-6-methyluracil.G-methyLB-[Z-(2-methylbutyl)]uracil 1965-br0mo-6-methyl-3-[2-(2-methylbutyl)]urac1l.6-methyl-3-[2-(2-methylpentyl)]uracil 2105-bromo-6-methyl-8-[2-(2-methylpentyl)]urae1l. 3-[2-(2,3-dimethylbutyl)]-6-n1ethyluracil 1 210 5-bromo-3-[2-(2,3-dimethylbutyl)]-6-methylurac11. 6-methyl3-[3-(3-methylpentyl)]uracil210 5-bro111o-6-methyl-3-[3- (3-methylpentyl)]urac1l.6-1nethyl-3-[2-(2-rnethylhexyl)]uracil 2245-bromo-6-methy1-8-[2-(2-methylhexyl)]urac1l. 3-[2-(2,3-di1nethylpentyl)]-6-methyluracil 224 5-br0m0-3-[2-(2,3-dLmethylpentyl)]-6-methylurae1l 6-methyl-3-[2-(2, 3,3-trimethylbuty1)]urac 224 5-b1'0mo-6-methyl-3f-[2-(2, 3,3-trunethylbutyl)]uraeil. 3-[2-(2 4-dimethylpentyl)]-6 methylurac11 2245-bromo-3-[2-(2, 4-d1methylpentyl)]-6-methylurac1l.6-methyl-3-[3-(3-methylhexyl)]uracrl 2245-bromo-6-methyl-8-[3-(3-methylhexyl)]urac1l. 3[3-(2,3-dimethylpentyl)]-6-methylur 224 5-br0mo-3-[3-(2,3-dimethylpentyl)]-6-methylurac1l.6-methyl-3-[3-(3-rnethylneptyl)]uracll 238 fi-bromob-methyl-d-[B-(3-methyl.hepty1)]urao1l. 3-[3-(3, 4-dimethylhexyl)]-6-methylurac 2385-bromo-3-[3-(3, 4d1methy1hexyl) -6-methylurao1l. 3-[3-(3,5-dimethylhexyl)]-6-methyluracil 238 5-bromo-3-[3- (3, 5-dtmethylhexyl)-6methylurae1l. 6-methyl-3-[3-(3, 4, 4-trimethyl entyl)]uraei l 2385-bromo-6-methyl-3-[3-(3, 4, 4-tr1methylpentyl)]urac1l.6rnethy1-3-[3-(3-methylnonyl) uracil 2665-bromo-6-methy1-3-[3-(3-methy1nonyl)]urac11.trmethyl-3-(I-methylheptyDuracil 238 5-bromo-6-rnethyl-3-(l-methylheptyl) uracll. v 3-(1, l-dimethylhexyl)-6-methyluraci1 2385-br0mo-3-(1, l-drmethylhexyl)-6-methy1urac1l.6-methyl-3-[3-(3-methy1octyl)]uracil 2525-bromo-6-methyl-3-[3-(3-methyloctyl)]urac11. 6-methyl-3- (3-octyl)uracil 238 5-bromo-6-methyl-3- (3-octyl) uracil.

C EXAMPLE 2.-PREPARATI ON OF 3TERT-BUTYL 5- CHLORO-G-VIETHY'LURACIL3-cyclohexyl-5-bromourac1l 40 3-cyclohexyl-5-chlorouracil 3-isopropyl-5-'bromouracil 3 -sec-butyl-5-bromouracil3-sec-butyl-5-chlorouraci1 mixed in a 1:6 to 6:1 ratio, preferably a 1:2to 2:1 ratio.

In order that the invention may be better understood, the followingexamples illustrating the preparation of compounds and the preparationand use of herbicidal compositions containing them are given:

EXAMPLE 1.PREPARATION OF 5-BROMO-3-SEC- BUTYL-(i-METHYLURACIL A solutionof 182 parts of 3-sec-butyl-6-methyluracil in 700 parts of acetic acidcontaining 82 parts of sodium acetate was treated with 160 par-ts ofbromine. After standing overnight, the mixture which contained somesolid,

Eight parts of chlorine are added to a stirred solution of 18.2 parts of3-tert-butyl-6-methyluracil in parts of glacial acetic acid. Thetemperature is maintained below 30 C. during this addition. The solutionis stirred hour longer at room temperature, then poured into ice water,whereupon a solid separates. This solid is collected by filtration,washed with water, dried, and is then recrystallized from a mixture ofcyclohexa-ne and ethyl acetate. The pure3-tert-butyl-5-chloro-6-methyluracil melts at 184 C.

EXAMPLE *3.PREPARATION 0F 3-SEC-BU1YL-5- 'CHLORO-G-METHYLURACIL Amixture of 182 parts of 3-sec-butyl-6-methyluracil, 500 parts of glacialacetic acid, and 82 parts of sodium acetate was stirred at 20-25 C.while parts of sulfuryl chloride were added over a one-hour period.Stirring was continued for one hour longer, after which the reactionmixture was evaporated and the resulting solid recrystallized from anethanol-Water mixture to give 3-sec-butyl-5- chloro-6-methyluraci1 as acrystalline solid melting at 153-155 C.

5-chloro uracils corresponding to the 5-bromo uracil counterparts listedin the table under Example 1 above can be readily prepared in a fashionsimilar to either Example 2 or this example by substituting the amountsof the 3,6-substituted uracil starting reactants, where different, shownin the table of Example 1 for the 3-tert- 'butyl--methyluracil ofExample 2 or the 3-sec-buty1-6- methyluracil hereof.

EXAMPLE 4.-PREPARATION OF 5-IODO3- ISOPROPYL-G-METHYLURA CIL A mixtureof 168 parts by weight of 3-isopropyl-6- methyluracil, 1000 parts byweight of acetic acid, and 253 parts by weight of iodine is stirred at100 C. as 75 parts 1 l by weight of fuming nitric acid are graduallyadded. When the addition is complete, the dark colored solution isrefluxed for about one-half hour and then cooled to icebath temperature.

Excess iodine which precipitates is filtered off and the filtrate isdiluted with 400 parts by weight of cold water. The iodine remaining insolution is reduced to iodide ion by adding a saturated solution ofsodium bisulfite until the solution becomes colorless.

The aqueous solution is extracted with 6000 parts by weight of methylenechloride. The organic layer is separated, washed with saturated sodiumbicarbonate solution, and then dried with 200 parts by weight ofmagnesium sulfate.

The 5-iodo-3-isopropyl-6-methyluracil is recrystallized fromacetonitrile. It melts at 181 C.

S-iodouracils corresponding to the 5-bromouracil counterparts listed inthe table under Example 1 above can be readily prepared in a fashionsimilar to this example by substituting the amounts of the3,6-substituted uracil starting reactants, where different, shown in thetable of Example l for the 3-isopropyl-6-methyluracil hereof.

EXAMPLE 5.PREPARATION F '5-FLUORO-3- ISOPROPYL-G-METHYLURACIL A mixtureof 102 parts of isopropyl urea, 700 parts of benzene, 4 parts ofp-toluenesulfonic acid, and 148 parts of ethyl u-fiuoroacetoacetate(caution, highly toxic) is stirred at reflux for eight hours while thewater given off by the reaction is collected in a suitable trap byazeotropic distillation.

The Water is removed and a solution of 64.8 parts of sodium methoxide in200 parts of absolute ethanol is gradually added. Refluxing is continuedfor an additional half hour. The mixture is cooled to about 15 C. Tothis is added 1200 parts of ice and water, and 5 parts of activatedcharcoal. After a short period of rapid stirring, the mixture isfiltered. The aqueous layer containing the sodium salt of the desiredproduct is separated and gradually acidified to a pH 5 With dilutesulfuric acid while stirring.

The resulting white solid is filtered oft" and recrystallized from watercontaining ethanol. After filtering and drying theS-fluoro-3-isopropyl-6-methyluracil thus produced melts at 176.5177.5 C.

5-fluorouracils corresponding to the S-bromouracil counterparts listedin the table under Example 1 above can be readily prepared bysubstituting the appropriate substituted ureas in equivalent amounts forthe isopropyl urea used in the reaction of this Example 5.

EXAMPLE 6 Percent 3-tert-butyl-S-chloro-6-methyluracil, Na salt Sodiumlauryl sulfate 2 Water 78 The solution is prepared by dissolving the twosoluble salts in the Water, with agitation and adding a small amount ofsodium hydroxide to maintain a pH of 12. This solution is suitable forquick dilution to desired spray levels.

Other soluble salts suitable for preparation of water concentrates are5-bromo-3-sec-butyl-6-methyluracil, sodium salt5-chloro-3-isopropyl-6-methyluracil, tetrabutylammonium salt5-bromo-3-isopropyl-6-methyluracil, potassium salt5-bromo-3-isopropyl-6-methyluracil, trimethyldodecylammoniurn salt Thisaqueous solution is used for post-emergence weed control. Aconcentration of 1.0 pound of active ingredient per acre in 30 gallonsof water gives excellent control of crabgrass, pigweed, velvet weed, andfiower-of-an hour.

At concentrations of 10 to 20 pounds per acre in 80 gallons of water,this composition gives excellent control of a Wide variety of annualbroadleaved and grass weeds growing in railroad yards on railroadballast.

EXAMPLE 7 Percent 5-bromo-6-methyl-3-(3-pentyl)uracil 28.0 Sodium ligninsulfonate 15.0 Hydrated attapulgite 2.0 Disodium phosphate 0.8 Sodiumpentachlorophenate 0.5 Water 53.7

The above ingredients are mixed and pebble-milled or sand-milled untilthe average particle size of the active material is substantially lessthan 5 microns. The resulting stable thixotropic suspension does notcake and can be readily diluted with water to form a dilute, very slowsettling suspension which requires no agitation during application.

This aqueous suspension, applied as a directed spray at l to 3 pounds ofactive ingredient per acre in gallons of water, gives good pre-emergencecontrol of barnyardgrass, mustard species, and jungle rice in sugarcane.

Other compounds of the invention which can be formulated in a likemanner are 5-iodo-3 -isopropyl-6-methyluracil5-chloro-6-methyl-3-(3-pentyl)uracil 5 -bromo-3-sec-butyl-6-methyluracil5 -bromo-6-methyl-3-( 2-pentyl)uracil 5-brorno-3- [3 ,5 -dimethylhexyl]-6-methyluracil 5-chloro-3-[3,5-dimethylhexyl]-6-methyluracil 33,5-dimethylhexyl] -5 -iodo-6-methyluracil EXAMPLE 8 Percent5-bromo-3-sec-butyl-6-methyluracil 4O Soya lecithin 3 Substantiallyaliphatic, low viscosity mineral oil, e.g.,

kerosene or diesel oil 57 The oil suspension is prepared by pregrindingthe active material and mixing it with the other components withagitation, or by blending all the components together, thenpebble-milling or sand-milling them to reduce the particle size of theactive component. The product is suitable for dilution with weed oils toform an oil spray.

This formulation is diluted with 80 gallons of an herbicidal oil such asLion Herbicidal Oil No. 6 and applied at 12 pounds of active ingredientper acre for general overall Weed control along Cyclone fences andrailroad ballast.

Good control is obtained for several months. Quickgrass, cheat,witchgrass, buttonweed, and jimson weed are controlled.

Other compounds of this invention which can be formulated in a likemanner are 5 -bromo-3 -is opropyl-G-methyluracil 5-chloro-6-methyl-3-(2-pentyl)uraci1 5-bromo-3-tert-butyl-6'methyluracilEXAMPLE 9 Percent 5-chloro-3-isopropyl-6-rnethyluracil2,4,S-trichlorophenoxyacetic acid propylene glycol butyl ether ester 10Mixed polyoxyethylated sorbitan monooleate and ethylenediamine dodecylbenzene sulfonate 5 Synthetic fine silica These ingredients are blended,micropulverized, and reblended.

This oil dispersible powder is used to maintain weedfee areas aroundelectric power poles by dispersing it in Lion Herbicidal Oil No. 6 andspraying it. A weed infestation of blackberry, honeysuckle, goldenrod,Speedwell, poison ivy, pokeweed, corn cockle, crabgrass and panic grassis controlled by use of 15 pounds (active) per acre of this formulationin gallons of oil.

13 EXAMPLE '10 Percent 3-sec-butyl-5-chloro-6-methyluracil, Na salt 25Granular 8-15 mesh attapulgite clay 75 Percent5-bromo-3-isopropyl-6-rnethyluracil 40 Anhydrous sodium sulfateNon-swelling Ca, Mg bentonite 49 Alkyl naphthalene sulfonate, Na salt 1These components are formulated as 4 to 8 mesh granules by blending andgrinding the components, then moistgranulating them, followed by dryingand screening.

The granules are broadcast at a level of 10 pounds of active ingredientper acre for the excellent control of oak brush growing on light sandysoil.

EXAMPLE 12 Percent 5-chloro-3-isopropyl-6-methyluracil 20 Attapulgiteclay 78 Alkyl naphthalene sulfonic acid, Na salt 1 Lignin sulfonic acid,Na salt 1 These ingredients are mixed in a ribbon blender untilhomogeneous and then charged to a pug mill, where sulficient water isblended in to form a thick paste. The paste is discharged from the pugmill in the form of extrusions which are dried and broken by a rotarycrusher into irregular granules.

Other compounds which can be formulated like Exam ples 11 and'l2 are 5-bromo-6-methyl-3 3-( 3-methylpentyl) ]uracil 5-chloro-3- [2- (2,3-dimethylbutyl) ]-6-methyluracil EXAMPLE 13 The granular compositions ofExamples 11 and 12 are applied by hand or by specially built spreaders.At concentrations of 25 pounds of active ingredient per acre, theycontrol broadleaf and grass weeds in lumber yards, along railroadrights-of-way, in fire lanes and around billboards, and in parking areasand roadsides.

They can be applied as soil treatments, at 20 pounds of activeingredient per acre, for the control of such woody plants as privet,elm, ash, oak, maple, and willow. This concentration also gives controlof germinating annual weeds and established perennial weeds such asquack grass and plantain.

EXAMPLE 14 Percent 3-isopropyl-5-chl0ro-6-methyluracil 25 Anhydroussodium sulfate 10 Sodium lignin sulfonate 10 Ca, Mg bentonite 55 Thesecomponents are blended and micropulverized, then moistened with 1820%water and extruded through die holes. The extrusions are cut intopellets and then dried.

These pellets are useful for weed control along highway guard rails,around bridges, Cyclone fences, and high way signs. They are applied byhand, at 10 to 25 pounds of active ingredient per acre. Excellentcontrol of such woody plants as oak, maple, sweet gum, and willow isobtained.

EXAMPLE 15 Percent 5-bromo-3-sec butyl-6-methyluracil 50 Na SiOanhydrous 21 K 00 anhydrous 21 Dioctyl sodium sulfosuccinate 2 Sodiumlignin sulfonate 5 Finely divided synthetic silica 1 These ingredientsare blended, micropulverized and re blended. An application of 10 pounds(active) in gallons of water per acre controls crabgrass, foxtail, watergrass, Indian grass, goldenrod, asters and ragweed on an industrialsite.

A directed pre-emergence spray of one pound (active) in 40 gallons ofwater controls crabgrass, water grass, foxtail, mustard, pigweed andlambsquarter in ratoon sugar cane 12 inches high.

Other uracils which can be formulated in like manner include 5-bromo-3-isopropyl-6-methyluracil 3-tert-butyl-5-chloro-6-methyluracil5-bromo-3-tert-butyl-6-methyluracil 5-iodo-6-methyl-3-( 3-pentyl)uracil5-chloro-6-methyl-3-(3-pentyl)uracil 5-bromo-6-methyl-3-(3-pentyl)uracilEXAMPLE 16 Percent Technical 5-bromo-3-isopropy1-6-methy1uracil 85.5Alkyl naphthalene sulfonic acid, Na salt 2.0 Calcium salt of partiallydesulfonated lignin sulfonic acid 0.5 Powdered gypsum (CaSO -2H O) 2.0Precipitated tricalcium phosphate 2.5 Attapulgite clay 7.5

These components are blended and micropulverized until the product showsless than one percent retention on a 325 mesh screen when wet screened.

This formulation, applied at the rate of 15 pounds (active) in gallonsof water, gives excellent control of broadleaved weeds such as plantain,dandelion, dock, smooth brome, Indian grass, and broomsedge growingalong railroad rights-of-way. Excellent residual weed control isobtained.

For a tank mix, five pounds of this powder are dispersed in 60 gallonsof water to which are added 10 pounds of a polyoxyethylated alkylmercaptan. One week after application, excellent contact burn is notedon annual bluegrass, Kentucky bluegrass, seedling Johnson grass,crabgrass, ragweed, wild mustard and cocklebur growing along a fencerow. Extended residual control of these species is obtained.

EXAMPLE 17 is obtained. The treated trees thrive.

EXAMPLE 18 I Percent Technical 95 5-bromo-3-sec-butyl-6-methylnracil-85.5 Alkylnaphthalene sulfonic acid, Na salt 3.0

Sodium salt of partially desulfonated lignin sulfonic acid 1.5 Basicmagnesium carbonate 2.0 Fine silica (silica aerogel) 2.0 Attapulgiteclay 6.0

These components are blended and micropulverized until the product showsless than one percent retention on a 325 mesh screen when wet screened.

Ten pounds of this formulation are dispersed in 100 gallons ofherbicidal oil (e.g., Lion Herbicidal Oil No. 6). When this mixture isapplied post-emergence to one acre around lumber yards, quick kill ofthe Weed population is obtained, followed by extended residual weedcontrol. Crabgrass, bluegrass, cinquefoil, goldenrod, Spanish needle,Bermuda grass, seedling Johnson grass and foxtail are controlled.

EXAMPLE 19 Ten pounds of 5-bromo-3-sec-butyl-6-methyluracil as the 80%wettable powder of Example 17 and 2 pounds of4,6-dinitro-ortho-secondary butylphenol in 4 gallons of oil are blendedas a tank mix and applied at 12 pounds of active herbicide per acre in100 gallons of water to weeds growing along fence rows. Quick kill ofannual and perennial broadleaf and grass weeds is obtained, withexcellent residual weed control.

EXAMPLE 20 Percent 5-brorno-3-sec-butyl-6-methyluracil 3N-(m-chlorophenyl)carbamic acid, isopropyl ester 24 Sodium dodecylbenzene sulfonate 1 Sodium N-methyl-N-palrnitoyl taurate 1 Attapulgiteclay 71 This formulation is used for the pre-emergence control ofgerminating annual grass and broadleaf weeds in sugar cane. Anapplication of 4 /2 pounds (active) per acre gives good control ofcrabgrass, foxtail, rice grass, seedling Johnson grass, and pigweed,without injury to the cane.

EXAMPLE 21 The formulation of Example 6 is applied to ponds or lakes insuch a manner that a uniform concentration of 5 parts per million ofactive material in the water is obtained. This concentration results inthe control of sub- 16 merged aquatic weeds such a pondweed (Potumogetonspp.), water milfoil (Myriophyllum spp.), stonewort (Chara spp.),coontail (Ceratophyllum spp.), and bladderwort (Utricularia spp.). 5 Iclaim:

1. A compound selected from the group consisting of (21) compounds ofthe formula where:

References Cited UNITED STATES PATENTS 1/1966 Crawford 260260 X OTHERREFERENCES Buckendorif, Ann., vol. 385, 1911, pages 314327.

NICHOLAS S. RIZZO, Primary Examiner. M. U. OBRIEN, F. A. MIKA, AssistantExaminers.

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF (A) COMPOUNDS OF THEFORMULA